We’re just beginning to appreciate the depth of the ocean’s wonders, as demonstrated by film director James Cameron’s recent seven-mile free fall to the lowest point of the Mariana Trench, roughly 50 times the size of the Grand Canyon.

While Cameron’s not eager to promote deep-sea tourism, inspired travelers might be surprised by how much we already have to gawk at below the waves. The coolest underwater attractions include ancient ruins, World War II shipwrecks, art, and kitsch—and you don’t necessarily need to be a scuba diver to enjoy them.

Swimming in Belize’s Blue Hole or sidling up to whale sharks make for memorable excursions, but those kinds of natural phenomena and wildlife are a whole other story. Instead, we’re highlighting the surprising array of man-made attractions under the sea that don’t depend on Mother Nature (unless you count an earthquake or two).

Whatever your snorkeling or diving ability, there’s something to see off the southern coast of the candy-colored island Curaçao. A submerged tugboat is easy bait for beginners, while the more advanced can dive deeper to reach car piles about 90 feet below the surface. These ’40s and ’50s models were junked in an ill-conceived attempt at reef building. Where sea life didn’t quite flourish, photo-ops do: you, behind the wheel of a rusty Chevy.

You don’t need to get wet to enjoy Florida’s campy Weeki Wachee Mermaid Show, whose synchronized swimmers have been donning fabric tails since 1947. Another kind of artistry is on display at Cancún’s Underwater Museum, which opened in November 2010 with hundreds of sunken life-size human figures. Corals are gradually transforming these statues into living reefs to haunting effect.

Google has even turned its attention underwater, partnering in the Catlin Seaview Survey, which maps the ocean floor in the vein of Google Street View. And even if Cameron won’t expand the tourist offerings, you can bet Sir Richard Branson will, with (what else?) Virgin Oceanic, testing now.

But there’s no need to wait. Take the plunge now to explore these cool underwater attractions—it’s a brave new world down there.

Museo Subacuático de Arte, Cancún, Mexico

British artist Jason deCaires Taylor’s under-the-sea museum features more than 400 pieces molded from pH-neutral concrete and sunk in Cancún’s National Marine Park off Isla Mujeres (a much larger endeavor than his first sculpture park in Grenada’s Moliniere Bay). Look out for the orange coral–studded “Man on Fire” and Terracotta Army–esque “Silent Evolution.” Corals and sea life will gradually stake a claim on the figures, transforming them into living reefs to surreal effect. You can visit via snorkel, scuba, or glass-bottomed boat.musacancun.com

Parco Archaeologico Sommerso di Baia, Pozzuoli, Italy

Pompeii doesn’t have the lock on ancient Italian trauma. Thanks to bradyseism—the gradual raising or lowering of earth due to filling magma chambers—the neighborhood of Baia, 30 minutes west of Naples, now rests in about five to 15 feet of water. Guided tours for both snorkelers and divers cover eight underwater (and four terrestrial) sites like Villa Protiro and Portus Julius. Intricate black-and-white mosaic floors, loose statues, and frescoes mingle with sea stars and anemone shoals...for now. As recently as 1984, the sea floor raised six feet.

Truk Lagoon, Micronesia

At the top of even the most casual wreck enthusiast’s bucket list, Truk (a.k.a. Chuuk) was the forward stronghold of Japan’s Imperial Navy during World War II before it was bombed into oblivion in February 1944. The coral-encrusted ghost fleet (some 60 ships, 275 airplanes)—with gas masks, ammunition, guns, and bones still rattling inside—litters the sandy floor at an average depth of 65 feet. The lagoon’s calm waters host reef sharks and a rainbow of fish, as seemingly in paradise as the divers photographing rusted artillery tanks aboard the San Francisco Maru and the shattered hulk of the I-169 Shinohara submarine.visit-fsm.org

Neptune Memorial Reef, Key Biscayne, FL

Introducing the first cemetery that requires PADI certification to pay your respects. The founding Neptune Society has taken burial at sea to a monumental level with what will ultimately be the world’s largest man-made reef: 16 acres sprawled under 50 feet of water about three miles east of Key Biscayne, near South Beach. Modeled after Atlantis, with stone lions guarding an entrance canopy and porticos, the reef has space in its first phase for 850 “placements”—cremated remains mixed with concrete and put into niches or molded into shell and coral shapes on the sea floor. The ultimate capacity will reach 125,000.nmreef.com

Port Royal, Jamaica

It wasn’t rum or syphilitic excess that undid the 17th-century Caribbean’s notorious hotbed of piracy and privateering, so dubbed “the Wickedest City on Earth.” It was bad urban planning. Port Royal was built on a sand spit, and when an earthquake struck on June 7, 1692, liquefaction caused 33 acres, streets and all, to sink. Today, it’s one of the New World’s best nautical archaeological sites, with depths reaching 40 feet. Consult dive shops for permits to explore paving stones, parts of the former city wall, and nearby wrecks.visitjamaica.com

Yonaguni Monument, Okinawa, Japan

A sport diver tracking hammerhead sharks in 1987 discovered a megalithic temple 82 feet under the East China Sea: solid rock slabs, carved with near right angles in a stepped pyramidal structure; ancient walls and water channels; stone tools and carvings. Or did he? Japanese scientists proclaimed it the Lost Continent of Mu. Dissenters chalked it up as a unique, though natural phenomenon, like the basalt columns of the Giant’s Causeway. What’s not up for geological debate: the flights of fantasy you get from diving here.reefencounters.org

Underwater Post Office, Vanuatu

At the world’s first underwater post office, 150 feet out and nine feet down off marine sanctuary Hideaway Island, it’s not slow-moving lines of humans you have to contend with but schools of shimmering fish. Cyclone Jasmine damaged the structure in February 2012, so for now scuba-gear-clad mailmen have been replaced by an unmanned yellow post box; about $4 still gets you a waterproof postcard mailed anywhere in the world.vanuatupost.vu

Weeki Wachee Mermaid Show, Spring Hill, FL

Fed by the massive Weeki Wachee Springs, the Mermaid Show Theater an hour north of Tampa is an aquatic cousin to the terrestrial tackiness of road-trip classics like South Dakota’s Corn Palace and Route 66’s dusty concrete dinosaurs. Campy, you betcha! It’s a slice of Americana layered on thick. And yet, in the right mood, its old-time charm and balletic prowess—and occasional stage crash by a pirouetting manatee—is enchanting nostalgia, an act largely unchanged since pretty girls first donned fabric tails in 1947.weekiwachee.com

Florida Keys Shipwreck Trail

Stretching 120 miles from Key Largo to Key West, this aggressive artificial reef program supplements the area’s shallow, fish-filled reefs and wrecks of early 1700s Spanish galleons. Free dive logs highlight the main sites, such as the massive radar dishes of the 524-foot-long missile tracker USS Vandenberg, host to an underwater photo exhibit. North of Key Largo, near Miami, The Spirit of Miami—an entire Boeing 727 jetliner sunk in Biscayne Bay in 1993—was subsequently lost during a tropical storm and rediscovered in multiple pieces in 2010.fla-keys.com/diving

Vaersenbaai Car Piles, Curaçao

Divers know the candy-colored island of Curaçao for the Marine Park all along its southern coast, offering easy shore dives and snorkeling, sheer drop-offs, and coral bays. There are wrecks for beginners (a cutesy tugboat) and, for the more technically skilled, car piles roughly 90 feet down. Classic rides from the ’40s and ’50s were junked in Vaersenbaai along with cranes and construction equipment in an ill-conceived attempt at reef building. But where sponge and coral didn’t quite flourish, photo-ops do—namely you behind the wheel of a rusty Chevy.curacao.com

Pharos Lighthouse and Cleopatra’s Palace, Alexandria, Egypt

Although plans for an underwater museum seem to have sunk, divers can still peer through the murky shallows of Alexandria’s Eastern Harbor (about 15–20 feet deep) to glimpse wonders from the ancient world, including 56-ton massive granite blocks believed to be from the Pharos Lighthouse. Treasures from Cleopatra’s royal boudoir, destroyed in earthquakes and tsunami in A.D. 365, include headless sphinx, carved parts of a broken sarcophagus, and plenty of amphora. Elsewhere in the bay, a World War II–era plane and Roman merchant vessels molder.montazawatersports.com

Martha’s Quarry, Lebanon, TN

One of the rare inland dive spots not overrun with pleasure craft or fishermen, Martha’s Quarry lies a half-hour east of Nashville and offers 40 acres of spooky industrial wreckage in chilly water about 50 feet deep. Swim down stairwells in the giant four-story rock crusher building, past giant catfish and a conveyor belt, and through an intact kitchen with a range, a TV, and a deep freezer—all entombed when miners struck water, flooding everything so fast that none of the equipment could be removed.Sea Lover Scuba; (615) 860-9390

Jules Undersea Lodge, Key Largo, FL

Recent mega-luxe projects like Fiji’s Poseidon Undersea Resort or Dubai’s Hydropolis appear to have tanked, but this 1970s marine research station turned campy two-bed, one-bath lodge keeps on treading as the world’s only true underwater hotel. (That’s Jules as in Verne, author of 20,000 Leagues Under the Sea.) Guests must be PADI certified, or take a three-hour crash course, to check in 21 feet down in the mangrove-filled Emerald Lagoon. Once there, you’ve got 42-inch picture windows, hot showers, and all the compressed air and screenings of Abyss you can handle.jul.com

Lake Lygnstøylsvatnet, Norway

A 1908 landslide jammed the Lygna River in the precipitous Norangsdal Valley near Øye, forming a pristine mountain lake—and a prime spot for underwater photography. Beneath the cold, glassy waters, divers can explore remains of alpine huts with birch-bark roofs and swim under a stone bridge that was used to cross the river before it was inundated by it. Rich with algae and greenery, a collection of dead tree trunks is known locally as the Troll Forest. Just be sure to bring a dry suit.visitnorway.com

Atlantis Submarine Cruises, Honolulu

Just because you can’t dive doesn’t mean you can’t be Jacques Cousteau—at least for 90 narrated minutes in air-conditioned comfort. Atlantis’s 48- and 64-passenger recreational submarines ply the depths near Waikiki, with sunken ships, colorful coral, and plenty of sea life passing your porthole. Additional routes run off Kona and Maui, where you might catch some humpback whales from December to May. Minus the mermaids, it’s what Disneyland’s submarine ride was always meant to be.atlantisadventures.com

Il Cristo degli Abissi, San Fruttuoso Bay, Portofino, Italy

Cast in bronze by Guido Galletti and sunk in 1954, the nearly nine-foot-tall Christ of the Abyss gets around. There are copies stretching their arms peacefully toward the heavens both underwater in Key Largo and on land in Grenada, the latter given as a gift to the islanders following the 1961 sinking of Costa Cruise Line’s Bianca C. Following a 2004 restoration that replaced a severed hand, the original rests again in 50 feet of water just offshore from San Fruttuoso’s 11th-century abbey. On calm days snorkelers and landlubbers (with polarized glasses) can catch a glimpse as well.sanfruttuoso.eu

At this seafood restaurant you don’t choose your dinner, you watch it swim by—16 feet below the surface via 180-degree panoramic views. But with only 14 seats and an expected life span of 20 years (it was built in 2005), not to mention The Maldives’ own rising ocean threat, you might want to consider a reservation at the world’s only all-glass underwater restaurant sooner rather than later.conrad.hilton.com

Lake Minnewanka, Banff National Park, Canada

Third time’s a charm—as far as creating cool dive sites goes. Calgary Power Co. dammed Devils Canyon in 1941, raising the water level of the lake by more than 100 feet and inundating not only the two previous dams (a log one from 1895 and a 1912 concrete job) but also the entire Minnewanka Landing townsite, a tourist destination in its day. Today, divers jostle with fishermen to get a glimpse of the old wharf and bridge, a two-story powerhouse and 1912 dam, plus house foundations and the local hotel. Highlights include fireplaces, wood-burning stoves, and even an intact picket fence.pc.gc.ca

Shanghai Ocean Aquarium, Shanghai

Visitors to this Pudong museum can easily descend more than 500 feet—with no PADI certification necessary. At 155 meters, the basement-level aquarium tunnel winds through deep ocean and coastal exhibits, kelp caves and coral reefs, as turtles and manta rays and some 450 species of fish swirl overhead. Time your visit to the twice-daily shark feedings for killer snaps.sh-aquarium.com

Lake Jindabyne, Snowy Mountains, New South Wales, Australia

Not all residents of East Jindabyne may be aware that beyond the roads that seem to disappear at water’s edge are remnants of the original township that never made the move east. Divers who brave the deep—and the silt (mostly the silt)—may be rewarded with the phantasmagoric fade-in and fade-out of a rusting truck still in its garage, a four-poster bed in a crumbling farmhouse, or an errant shoe, bottle, or pipe haunting the gray-green gloom.abyss.com.au

Enchanted Forest, Table Rock Lake, Missouri

Table Rock Dam literally swamped the town of Oasis under 100 feet of water to spectacular results: a sunken oak grove that harbors a multitude of aquatic life, from snails to giant catfish, yellow perch to largemouth bass, blue-green crayfish, and rare freshwater jellies. Think of it as the Midwest’s Great Barrier Reef.whiteriverdiveco.com

Bikini Atoll, Marshall Islands

A hot destination among wreck divers since reopening to tourism in 1996, the 23 islands of the Bikini Atoll are no longer “hot” in the radioactive sense (Operation Crossroads vaporized three of them with atomic bomb tests from 1946 to 1958). Live-aboard cruises allow access to almost 20 naval warships and submarines in the UNESCO-protected area, including the world’s only scuba-accessible aircraft carrier, the 39,000-ton USS Saratoga, as well as the Japanese battleship HIJMS Nagato, flagship of the Imperial Fleet during Pearl Harbor. Both were sunk by the underwater Baker blast.bikiniatoll.com

Lake Jocassee, Salem, SC

The owners of the Attakulla Lodge Hotel refused to sell their land or allow its razing despite rising waters from a newly built dam. That was 1973. Fast-forward to the present, and 300 feet below in the chilly murk, its ghostly hulk rests largely unscathed right down to the peeling paint. Because of the depth, expert divers will have just enough time—maybe 20 minutes out of a 2.5-hour trip—to practice their Jordan dunk on the basketball court. In shallower waters, a nearby cemetery that was used as a location in Deliverance offers additional creepiness (and plastic skeletons).jocasseediveshop.com